Git: What is the purpose of `git reset`?

Scott Chacon, the author of ProGit, also has a helpful blog, and this particular entry on "git reset" is absolutely invaluable. Also see this blogpost by Mark Dominus.

ShowOff: PowerPoint/Keynote alternative?

According to Scott Chacon (also the author of the ProGit book and a senior developer at GitHub) near the end of this interview, the following inequalities exist in the world of presentation slides for software developers:

PowerPoint < Keynote < ShowOff

Actually, the entire interview (of Scott Chacon by Werner Schuster on 06 September 2010 at the Scottish Ruby Conference in Edinburgh) is interesting, covering such topics as the use of Erlang, Redis, and memcached in the GitHub infrastructure.

Node.js, Redis, Pub-Sub, WebSockets in one brief example

http://howtonode.org/redis-pubsub

That's a quick way to learn a bunch of stuff.

... Well, as of 2014 that's pretty much out-of-date, but the discussion thread has useful links.